T
HERMO
90 / 90 S
7CIRCUIT DIAGRAMS
7-1
7. Circuit Diagrams
7.1 General
The circuit diagrams (Fig. 7-2 and 7-4) show possible
circuits of the Thermo 90 heater with:
• with standard switch and harness wiring using
Deutsch connector and blower interlock wiring with
Deutsch connector – North American enclosure &
compact kits (see Fig. 7-2).
• with 7-Day 3-Program digital timer wiring without
Deutsch connector – German version (see Fig. 7-4).
The circuit diagrams (Figs. 7-3 and 7-5) show possible
circuits of the Thermo 90 S heater with:
• with standard switch and harness wiring using
Deutsch connector and blower interlock wiring with
Deutsch connector – North American enclosure &
compact kits (see Fig. 7-3).
• with 7-Day 3-Program digital timer wiring without
Deutsch connector – German version (see Fig. 7-5).
Fig. 7-1 shows the pin assignment (X1) for Thermo 90
and Thermo 90 S heaters.
CAUTION
The – poles must not be looped or reversed as some
components are controlled by negative polarity.
1 = Glow Pin +
2 = Temperature Limiter +
3 = Flame Sensor +
4 = Temperature Sensor +
5 = Circulation Pump +
6 = Combustion Air Fan +
7 = Combustion Air Fan –
8 = Circulation Pump –
9 = Temperature Sensor –
10 = Flame Sensor –
11 = Temperature Limiter –
12 = Glow Pin –
Fig. 7-1 Visual Inspection, Burner Rear Wall
View from rear
